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应用改进的定向凝固装置研究了Ａｌ－２ｗｔ－％Ｃｕ和Ａｌ－４ｗｔ－％Ｃｕ合金在阶跃和不同加速度线性变速生长条件下，定向凝固组织的动态转变。实验结果表明：尽管定向生长的胞－枝晶动态转变过程随加速度的降低而减缓，但胞晶组织都是在经历了一定的胞晶形貌扰动之后才发生快速失稳、分枝细化并向树枝晶组织过渡，加速度不同，由失稳胞晶演变成的树枝晶可具有多种分枝形式。
The dynamic transformation of oriented solidified structure of Al-2wt-% Cu and Al-4wt-% Cu alloy under linear velocity growth and step acceleration under different accelerations was studied with an improved directional solidification device. The experimental results show that although the dynamic transformation of cell-dendrite during directional growth slows down with the decrease of acceleration, the cell undergoes rapid instability and finely branching after experiencing some perturbation of the cell morphology The transition to dendrite structure, the acceleration is different, the dendrites evolved from the unstable cell dendrite can have a variety of branching forms.